Field of the Invention and Related Art Statement
This invention relates to an agglutination analyzing vessel for analyzing samples by means of agglutination patterns produced in the vessel due to immunological agglutination reactions, and more particularly to a vessel for identifying various kinds of blood types with the aid of agglutination patterns of blood corpuscles or for detecting various kinds of antibodies and antigens in sample solutions (like viruses, proteins or the like) with the aid of agglutination patterns of not only blood corpuscles but also particles of insolable materials such as latex, carbon or the like.
The conventional agglutination analyzing vessels for identifying the blood types or detecting the antibodies and antigens in sample solutions with the aid of the immunological agglutination reaction patterns have been made of solid material such as plastics and glass as stated in U.S. Pat. No. 4,303,616. FIG. 1A is a perspective view showing a microplate 1 made of plastics, in which there are arranged in a matrix matter a number of wells 2, each having a conical base surface 2a, and FIG. 1B is a cross sectional view cut along line a--a of FIG. 1A. FIGS. 2A.about.2E are schematic views showing in an enlarged scale a process of the immunological agglutination reaction effected in one of the wells 2 provided in the microplate 1. It should be noted that a plurality of fine engravings or steps are regularly formed in the inclined base surface 2a of the well 2 in order to form a stable substrate layer of particles which are uniformly deposited on the inclined base surface 2a of the well 2.
In order to detect and measure the HBs antigen in a test blood, there has been proposed a method stated as follows. As shown in FIG. 2A, a reagent solution 3 including particles 4, on which anti HBs antibodies have been bound, (for example, red blood cells of animals), and sample serum are introduced into the well 2 of the microplate 1 to form a test liquid which is then set in a stationary state. Thereafter, the particles 4 in the reagent solution 3 start to settle down in the analyzing vessel gradually and slowly to form an agglutination pattern or a non-agglutination pattern on the inclined bottom surface 2a of the well 2.
In the case of when the sample serum includes the HBs antigen, an antigen-antibody reaction is effected in the test liquid introduced in the well 2 not only when the particles 4 fall down in the solution 3 but also after the particles 4 have been settled on the inclined bottom surface 2a of the well 2. The particles 4 are agglutinated with each other and are deposited so as to be spread uniformly all over the inclined bottom surface 2a of the well 2 to form an agglutination pattern. FIG. 2B is a cross sectional view showing the well in which the agglutination pattern is formed on the inclined bottom surface 2a and FIG. 2C is a schematic plan view of the pattern viewed from the above.
In the case of when the sample serum does not include the HBs antigen, the particles 4 settling on the inclined bottom 2a of the well 2 roll down along the inclined bottom surface 2a of the well 2, since no antigen-antibody reaction has occurred in the test liquid. Thus, the particles 4 are collected at the lowest portion of the bottom surface 2a and a non-agglutination pattern as shown in FIG. 2D is formed thereon. FIG. 2E is a schematic plan view of the non-agglutination pattern viewed from above. In such a manner, the HBs antigen existing in the sample blood is detected by the difference of the particle patterns formed on the bottom surface 2a of the well 2.
However, in this method, since the particle pattern is formed with the aid of the natural sedimentation of the particles 4, in which the particle pattern is formed only depending on the specific gravity and temperature of the sample solution and the weight and dimension of the particle, it takes one or two hours until clear particle patterns are formed on the inclined bottom surface 2a of the well 2. Thus, the test cannot be conducted speedily.
Another known method for detecting and measuring the HBs antigen is to centrifuge the microplate containing a mixture of reagent particle solution and the sample serum therein. In this method, the sedimentation speed of the particles 4 contained in the test liquid is promoted by the centrifugal force.
According to this method, it is possible to promote the sedimentation speed of the particles in the test liquid but a bucket is necessary to set the microplate in the centrifuge, and further the centrifuge operation is not very easy. Thus, the test cannot be easily conducted.